Glass Fibre Mat and Products Containing Glass Fibre Mats

ABSTRACT

A glass fibre mat comprises glass fibres of a first kind, glass fibres of a second kind and a binding agent. Glass fibres of the first kind in this case are characterized by a mean fibre diameter of under 6 μm and compliance with the EC Protocol “ECB/TM/27 rev. 7” and glass fibres of the second kind by a mean fibre diameter of over 6 μm. The ratio between the weight component of glass fibres of the first kind and the weight component of glass fibres of the second kind is between 0.01 and 0.15. And the surface weight of the glass fibre mat is between 25 g/m2 and 80 g/m2. In a CV floor covering comprising a usable layer and a structural layer, the structural layer comprises a glass fibre mat of this kind provided with impregnation.

BACKGROUND OF THE INVENTION

The present invention relates to a glass fibre mat. It further relates to products containing glass fibre mats, particularly a CV floor covering comprising a glass fibre mat as a structural layer.

Glass fibre mats are known in multifarious embodiments and for various applications. Also known are customary methods of producing glass fibre mats from glass fibres and binders. A significant application of glass fibre mats is their use as a carrier material in floor coverings, particularly in CV (Cushioned Vinyl) floor coverings. During the production of CV floor coverings, the glass fibre mat is typically initially impregnated in a first step with a PVC paste (particularly Plastisol). For this purpose, the PVC paste is usually applied to the glass fibre mat by means of a coating knife in a predetermined layer thickness or with a predetermined surface weight (e.g. approx. 400 g/m²). A further layer of PVC paste is then applied to the glass fibre mat impregnated in such a way, wherein the surface weight of this second layer can typically lie roughly within the same order of magnitude as the impregnating coating. The back foaming, i.e. the application of an elastically flexible coating to the back side of the glass fibre mat, then takes place. The usable side can then receive a final finishing, for example by means of a coating of clear varnish or other special coatings. This kind of production of CV floor coverings has been known in the PVC industry for some time and is widely used in different variants.

Various requirements are made of the glass fibre mat forming the carrier layer in this respect, some of which are to some extent in conflict with one another. Hence, the glass fibre mat should exhibit good mechanical strength, namely both during the processing and also during the use of the floor covering designed and produced using said glass fibre mat. It is therefore important for both the PVC paste and also the back foaming to create an optimal mechanical connection with the glass fibre mat, so that these layers are prevented from separating from the glass fibre mat when the floor covering is in use. On the other hand, the PVC paste, which is applied to the glass fibre mat by means of a coating knife, as described above, must be prevented from penetrating through said glass fibre mat. This is because otherwise more or less noticeable lumps of PVC form on the back side of the glass fibre mat, where the backing foam is to be applied subsequently, which has a substantially adverse effect on the level of comfort when walking on the CV floor covering. Furthermore, as usual cost considerations play a part, both in relation to the production of the glass fibre mat and also in relation to the impregnation thereof with PVC paste, in which case the consumption of PVC paste for impregnation is crucially dependent on the thickness and the properties (pore volume, permeability, absorbability, pore size distribution) of the glass fibre mat.

BRIEF SUMMARY OF THE INVENTION

The present invention is aimed at providing a glass fibre mat which is ideally suited for use as a carrier material in a CV floor covering, in that is satisfies all the requirements described above in a practical manner and, to this extent, is superior to the prior art in its overall properties.

DETAILED DESCRIPTION OF THE INVENTION

This problem is solved according to the present invention, as indicated in claim 1, by a glass fibre mat comprising glass fibres of a first kind, glass fibres of a second kind and a binding agent, wherein the glass fibres of the first kind are characterized by a mean fibre diameter of under 6 μm and compliance with the EC Protocol “ECB/TM/27 rev. 7” and the glass fibres of the second kind are characterized by a mean fibre diameter of over 6 μm, wherein furthermore the ratio between the weight component of glass fibres of the first kind and the weight component of glass fibres of the second kind is between 0.01 and 0.15 and, in addition, the surface weight of the glass fibre mat is between 25 g/m² and 80 g/m².

In other words, therefore, a specific combination of synergistically interacting features is characteristic of the glass fibre mat according to the invention, such that it comprises various glass fibres connected to one another by means of a binding agent, namely relatively thin glass fibres of the first kind on the one hand, i.e. those with a mean fibre diameter of under 6 μm and, on the other hand, relatively thick glass fibres of the second kind, i.e. those with a mean fibre diameter of over 6 μ, wherein the weight component of glass fibres of the first kind in the glass fibre composition is significantly smaller than the weight component of glass fibres of the second kind, in that the ratio between the weight component of glass fibres of the first kind and that of glass fibres of the second kind lies between 0.01 and 0.15, wherein furthermore glass fibres of the first kind within the meaning of the criteria according to the EC Protocol “ECB/TM/27 rev. 7” (Biopersistence of Fibres; Intratracheal Instillation) are not biopersistent and the surface weight of the glass fibre mat lies between 25 g/m² and 80 g/m². The properties of the corresponding glass fibre mat make it particularly suitable, especially with regard to the use described above, although they also allow a use of the glass fibre mat according to the invention associated with significant advantages in a series of other applications, in which similar requirements are made of the glass fibre mat (see below). One aspect which is to this extent significant and entirely surprising in this context is that despite its relatively low surface weight of between 25 g/m² and 80 g/m², which is even lower than the typical surface weight of known glass fibre mats used and suitable for similar applications, which contain no microfibres, and therefore despite the smaller proportion of stronger glass fibres to this extent, compared with traditional glass fibre mats with only one kind of glass fibres, the glass fibre mat according to the invention exhibits no significant loss in terms of mechanical properties such as strength, in particular, wherein at the same time, however, the risk that (in the preferred application described above) PVC paste penetrates through the glass fibre mat and forms lumps on the back side is significantly reduced compared with the relevant prior art. At the same time, when the glass fibre mat according to the invention is used, compared with the state of the art, the surface of the finished floor covering can be improved by minimizing irregularities on the usable side. It should furthermore be emphasized that the need for PVC paste, which is required in order to impregnate the glass fibre mat, can be reduced when using the glass fibre mat according to the invention, namely without the bond between the glass fibre mat and the impregnation being adversely affected as a result of this. Because the microfibres, i.e. glass fibres of the first kind exhibiting a mean fibre diameter of under 6 μm are furthermore not biopersistent (see above), the glass fibre mat according to the invention and the products manufactured using it are non-hazardous from a health perspective; this is because the glass fibres released particularly during processing (particularly at raw edges) can cause no harm in the human body, because they are either not respirable (this is the case with glass fibres of the second kind) or, however, are dissolved in the body by bodily fluids (this is the case with glass fibres of the first kind). To this extent, although glass fibres of the second kind may likewise be non-biopersistent, they need not necessarily be so, which is an important aspect both with regard to flexibility, which concerns the glass used for glass fibres of the second kind, and also with regard to production costs.

Although the use of the glass fibre mat according to the invention, as discussed in detail above, is paramount when it comes to the manufacture of floor coverings, as far as the particular suitability of the glass fibre mat according to the invention is concerned, this is in no way the only possible use. Various aspects presented above, which characterize the glass fibre mat according to the invention, mean that this can also be used instead particularly advantageously for a series of other applications. Something to be particularly mentioned in this case is its use (in the manner of a traditional wallpaper) as a paintable ceiling and wall covering, with which an outstanding surface quality can be achieved with a very small (subsequent) application of paint, wherein furthermore the extremely low tendency for the paint to pass through the mat has a very favourable effect on the bond between the glass fibre mat acting as a ceiling or wall covering and the base concerned. The fact that a very good surface quality can be achieved with a very small amount of wall or ceiling paint is not only an economic aspect in this case. It also means that the weight of the ceiling and wall covering plus the coat of paint, i.e. the painted ceiling and wall covering, is relatively small, which for its part accommodates the bond of the glass fibre mat to the base. These advantageous criteria apply in a very similar manner when using the glass fibre mat according to the invention as the surface coating on a sheet of building material, particularly a mineral ceiling or wall panel, such that the glass fibre mat is applied to the preformed board at the factory (particularly by adhesion or surface lamination). This is because the specific structure of the glass fibre mat according to the invention prevents the adhesive from penetrating through from the back side to the front surface, i.e. the visible side, so that the surface quality of the visible side and the paint adhesion are not adversely affected by adhesive tracks. Likewise, due to its favourable properties, as described, the glass fibre mat according to the invention can be used particularly advantageously as a cover for interior elements, particularly of a motor vehicle, particularly as a cover panel or other interior facing.

The particular advantages of the glass fibre mat set out above are particularly distinct when the mean fibre diameter of glass fibres of the first kind is between 0.5 μm and 6 μm, preferably between 0.6 μm and 3.0 μm, particularly preferably between 0.6 μm and 1.5 μm.

Furthermore, according to another preferred development of the present invention, it is particularly favourable for the mean fibre diameter of the glass fibres of the second kind to be between 6 μm and 13 μm. Particularly in combination with the preferred dimensions of the glass fibres of the first kind, as indicated above, particularly outstanding material properties result, which make the corresponding glass fibre mat particularly attractive for the uses set out above.

Glass fibres of the second kind particularly preferably comprise C-glass and/or E-glass, wherein T-glass for glass fibres of the second kind is also highly suitable for various applications. It is particularly advantageous in this case for glass fibres of the second kind to comprise a mixture of at least two different kinds of glass fibre. If the mixture of glass fibres of the second kind in this respect comprises both C-glass and also E-glass, it is preferable for the proportion of glass fibres comprising C-glass in the mixture of glass fibres of the second kind to be greater than the proportions of glass fibres comprising E-glass, wherein the proportion of glass fibres comprising C-glass in the mixture of glass fibres of the second kind may even be substantially greater within the framework of the present invention than the proportions of glass fibres comprising E-glass. The ratio indicated above is in turn favourable with regard to the particular properties of the glass fibre mat according to the invention described above, as they are useful, particularly in flooring applications. For other applications, however, other ratios may also be entirely favourable, even up to a proportion of 100% of glass fibres comprising E-glass accounting for fibres of the second kind.

According to yet another aspect of the present invention, glass fibres of the second kind particularly preferably have a mean length/diameter ratio of between 500 and 2000. This proportion of glass fibres of the second kind bears a special relationship to the particular function thereof within the glass fibre mat, particularly with regard to mechanical strength (see above).

According to yet another preferred development of the present invention, the ratio between the weight component of glass fibres of the first kind and the weight component of glass fibres of the second kind for typical applications of the glass fibre mat according to the invention is preferably between 0.03 and 0.08, particularly preferably between 0.04 and 0.06. The aforementioned ratio is favourably less than 0.055, ideally less than 0.048. In turn, there result in this case quite particularly advantageous properties of the glass fibre mat according to the invention, particularly with regard to the possible use thereof as a carrier material in CV floor coverings with outstanding properties. In this respect, it is furthermore favourable for typical applications if the surface weight of the glass fibre mat lies between 40 g/m² and 60 g/m². For specific applications, very good results can be achieved, however, with values that differ from these, e.g. a ratio between the weight component of glass fibres of the first part and the weight component of glass fibres of the second kind of less than 0.03.

As far as the binding agent of the glass fibre mat according to the invention is concerned, there is significant latitude here, which may particularly take account of the subsequent use of the glass fibre mat according to the invention. Particularly advantageous binding agents are urea resins and polyacrylic acid binders. The binding agent may, however, also comprise polyacrylic acid. Outstanding properties result when the binding agent comprises a mixture of urea resin and a polymer dispersion or a mixture of polyacrylic acid binders and a polymer dispersion.

Likewise, considerable latitude exists on the other hand in relation to the weight component of the binding agent in the glass fibre mat, wherein to this extent the specific binding agent used in each case and also the use of the glass fibre mat can play a part. For the possible use of a CV floor covering as a carrier material, which is paramount in this case, a weight component of the binding agent of between 15% and 35%, preferably of between 20% and 30%, of the total weight of the glass fibre mat is advantageous.

The binder may, depending on the designated subsequent use of the glass fibre mat in each case according to the invention, contain an additive (or a plurality of additives), which may account for up to 50% of the total weight of the binder. The additive (or additives) may specifically modify or else optimize the properties of the binder in this case with regard to the individual determination of the glass fibre mat. Typical additives are, for example, kaolin and TiO₂. However, not only can the binder be technically optimized by additives, but additives are also capable of reducing costs by being able to make an expensive binding agent “go further”.

With regard to the relationships described above, it is advantageous for typical applications if the porosity of the glass fibre mat lies within the range of roughly 1000 l/m²s and roughly 3000 l/m²s, wherein a porosity of between roughly 1500 l/m²s and roughly 2500 l/m²s is particularly favourable. The above values for a preferred porosity are based on the measurement standard DIN EN ISO9237, namely for a differential pressure of 100 Pa.

The present invention according to the above embodiments does not relate exclusively to the untreated glass fibre mat. Instead, the invention also relates particularly to a glass fibre mat pretreated for subsequent specific further processing, particularly provided with additional impregnation, wherein the impregnating agent may be particularly a plastisol or another PVC-based means. Furthermore, the present invention also extends to the finished CV floor covering produced using the glass fibre mat according to the invention, which CV floor covering comprises a usable layer and a structural layer, wherein the structural layer comprises a glass fibre mat according to the invention provided with impregnation (see above). 

What is claimed is:
 1. A glass fibre mat comprising glass fibres of a first kind, glass fibres of a second kind and a binding agent, having the following features: glass fibres of the first kind are characterized by a mean fibre diameter of under 6 μm and compliance with the EC Protocol “ECB/TM/27 rev. 7”; glass fibres of the second kind are characterized by a mean fibre diameter of over 6 μm; and the ratio between the weight component of glass fibres of the first kind and the weight component of glass fibres of the second kind is between 0.01 and 0.15; the surface weight is between 25 g/m² and 80 g/m².
 2. The glass fibre mat according to claim 1, characterized in that the binding agent comprises urea resin, preferably a mixture of urea resin and a polymer dispersion.
 3. The glass fibre mat according to claim 1, characterized in that the binding agent comprises polyacrylic acid binders, preferably a mixture of polyacrylic acid binders and a polymer dispersion.
 4. The glass fibre mat according to one of the claims 1 to 3, characterized in that the mean fibre diameter of glass fibres of the first kind is between 0.5 μm and 6 μm, preferably between 0.6 μm and 3.0 μm, particularly preferably between 0.6 μm and 1.5 μm.
 5. The glass fibre mat according to one of the claims 1 to 4, characterized in that the mean fibre diameter of the glass fibres of the second kind is between 6 μm and 13 μm.
 6. The glass fibre mat according to one of the claims 1 to 5, characterized in that glass fibres of the second kind have a mean length/diameter ratio of between 500 and
 2000. 7. The glass fibre mat according to one of the claims 1 to 6, characterized in that the glass fibres of the second kind comprise C-glass, E-glass and/or T-glass.
 8. The glass fibre mat according to one of the claims 1 to 7, characterized in that the glass fibres of the second kind comprise a mixture of at least two different kinds of glass fibre.
 9. The glass fibre mat according to claim 8, characterized in that the mixture of glass fibres of the second kind comprises both C-glass and also E-glass, wherein the proportion of glass fibres comprising C-glass in the mixture of glass fibres of the second kind is preferably greater than the proportion of glass fibres comprising E-glass.
 10. The glass fibre mat according to one of the claims 1 to 9, characterized in that the ratio between the weight component of glass fibres of the first kind and the weight component of glass fibres of the second kind is between 0.03 and 0.08, preferably between 0.04 and 0.06.
 11. The glass fibre mat according to one of the claims 1 to 9, characterized in that the ratio between the weight component of glass fibres of the first kind and the weight component of glass fibres of the second kind is less than 0.055, preferably less than 0.048.
 12. The glass fibre mat according to one of the claims 1 to 11, characterized in that it has a surface weight of between 40 g/m² and 60 g/m².
 13. The glass fibre mat according to one of the claims 1 to 12, characterized in that the weight component of the binding agent is between 15% and 35%, preferably between 20% and 30%.
 14. The glass fibre mat according to one of the claims 1 to 13, characterized in that the porosity is 1000-3000 l/m²s, preferably 1500-2500 l/m²s.
 15. The glass fibre mat according to one of the claims 1 to 14, characterized in that it is provided with additional impregnation.
 16. The glass fibre mat according to claim 15, characterized in that the impregnating agent is plastisol.
 17. A CV floor covering having a usable layer and a structural layer, wherein the structural layer comprises a glass fibre mat provided with impregnation according to claim 15 or claim
 16. 18. Use of a glass fibre mat according to one of the claims 1 to 14 as a coating for interior elements, particularly of a motor vehicle, particularly as a cover panel or other interior facing.
 19. The use of a glass fibre mat according to one of the claims 1 to 14 as the surface coating on a sheet of building material, particularly a mineral ceiling or wall panel.
 20. The use of a glass fibre mat according to one of the claims 1 to 14 as the wall coating. 